The retrieval hypothesis as an explanation of induced retrograde amnesia

The present experiment tested the hypothesis that retrograde induced amnesia is due to retrieval failure and anterograde induced amnesia to encoding failure by providing recall cues which were expected to eliminate retrograde amnesia but worsen or have no effect on anterograde amnesia. The 80 subjects received auditory presentation of 10 lists, each composed of 15 four-letter words presented at a rate of 2s/item at 75 dB in a free-recall task, followed by a 72 s recall period. The amnesia-producing event was an outstanding item in serial position 8 presented at 115 dB (about the intensity of a loud shout) on half the lists. During the first half of the recall period subjects free-recalled, but during the last half they were given a list of the first (single cue) or the first two (double cue) letters of each word, to be used as aids to recall. To demonstrate induced amnesia, lists containing a loud item were compared to those not containing one. First half free recall performance indicated that large retrograde and anterograde effects were present for both cue conditions. Second half cued recall performance indicated that in the double cue condition retrograde amnesia disappeared and anterograde amnesia became larger. Cueing had much smaller effects in the single cue condition.     

Young Children’s Physiological Reactivity during Memory Recall: Associations with Posttraumatic Stress and Parent Physiological Synchrony

Autonomic reactivity is implicated in stress response and social engagement – both key components of posttraumatic stress disorder (PTSD) – but few studies have examined autonomic reactivity in pediatric samples, and no known studies have examined physiological synchrony among children with PTSD and caregivers. In a sample of 247 young children (94 girls, 153 boys), most (85%) of whom had exposure to trauma and 40% who met criteria for PTSD, we examined children’s patterns of respiratory sinus arrhythmia (RSA) at baseline and in response to a memory recall task, as well as correspondence between parents’ and children’s RSA. Children with PTSD demonstrated significantly higher reactivity than other groups during their recollection of a traumatic memory, but not during other memory tasks. Regarding synchrony, caregivers’ and children’s RSA were more significantly and positively correlated during the trauma recall task among children who had had exposure to a potentially traumatic event but did not meet PTSD criteria, suggesting physiological synchrony may be protective in contexts of trauma. Overall, findings demonstrate physiological reactivity differences among young children with PTSD. While more work is needed to understand the meaning of parent-child physiological synchrony, these data suggest that children’s psychopathology is associated with physiological synchrony processes among young children with exposure to trauma.     

Children's memory of events: effects of stress,age, time delay and location of interview

To examine the ability of children aged between 4 and 12 years to recall a stressful event (venipuncture) compared with a non-stressful event (demonstration of venipuncture), recall was tested after 6–8 weeks. Half also had recall tested after 2–7 days. Testing took place where the stressful event occurred (n=122) or at a neutral location (n=127). Children who experienced the stressful event were less likely to give inaccurate responses in free recall or to acquiesce to suggestive misleading questions. Apart from incorrect responses in free recall, correct responses increased and incorrect responses decreased with increasing age. Recall after 2–7 days was superior to recall after 6–8 weeks. Those who had an early and a late interview had better recall at the late interview than those who had a late interview only. The location of interview showed no effects on recall. © 1998 John Wiley & Sons, Ltd.     

Traumatic memories and pseudomemories in posttraumatic stress disorder

Intrusive imagery was investigated in survivors of motor vehicle accidents with (a) posttraumatic stress disorder (PTSD) and accurate recall of the trauma, (b) PTSD and amnesia of the trauma, (c) no PTSD, or (d) control participants who simulated PTSD. Imagery was precipitated by presentation of an audiotape of a motor vehicle accident. Whereas the traumatic imagery of participants who had accurate recall of their trauma was consistent with third party accounts of the trauma, the imagery of amnesic participants was inconsistent with these accounts. Participants were then interviewed about cognitive and emotional aspects of their responses. All participants with PTSD and simulators reported similar levels of imagery detail, involuntariness, re-experiencing, and emotional response, and reported higher levels than participants with no PTSD. Findings are discussed in terms of cognitive and contextual factors that can mediate accurate and inaccurate traumatic imagery. © 1998 John Wiley & Sons, Ltd.     

Stability of emotions for traumatic memories in acute and chronic PTSD

While memory for central factual information regarding an emotional event is considered to be relatively accurate, memory for emotions seem to be quite inaccurate (Christianson & Safer, 1995). We extended this line of research to examine memory for the emotional intensity surrounding a traumatic event (e.g., memory for the fear and horror of the event). We conducted a series of two studies. In Study 1, we examined memory for the emotional intensity of the traumatic event in recent sexual or non-sexual assault victims with acute PTSD at 2 and 12 weeks following the assault. In Study 2, we compared memory for emotional intensity in sexual and non-sexual assault victims with either acute or chronic PTSD at initial assessment and 12 weeks later. For both studies, participants were asked to recall general emotional intensity, fear intensity, and dissociative intensity of the traumatic event. Results suggested that memory for the fear of the traumatic event did not fluctuate over time. However, memory for the general emotional and dissociative intensity did fluctuate over time, decreasing for individuals with acute PTSD and increasing for individuals with chronic PTSD.     

High-priority event instructions affect implicit and explicit memory tests

Previous work has shown that instructing subjects to give special priority to one target event in a list enhances recall for that event, but impairs recall for the events immediately preceding it (Tulving, 1969). We examined the benefit of high-priority instructions, and the retrograde amnesia for previous items, in three experiments that included two explicit tests of memory (free recall and cued recall with word-stem cues) and an implicit test (word-stem completion). Experiments 1 and 2 revealed a beneficial effect of high-priority instructions on memory for the target events in both free recall and primed word-stem completion. Retrograde amnesia for previous events was either absent (Experiment 1) or modest (Experiment 2) in free recall; however, no evidence for amnesia occurred on the implicit test. In Experiment 3, we asked if the benefit of high-priority instructions on the implicit test was due to contamination from intentional recollection, by employing the logic of the retrieval-intentionality criterion via a levels-of-processing manipulation. The results showed a beneficial effect of high-priority instructions on free recall, word-stem cued recall, and word-stem completion. Level of processing affected the two explicit tests, but not the implicit test, indicating that it induced incidental retrieval. We conclude that the benefit of high-priority instructions occurred on all three tests used in these experiments. In contrast, the phenomenon of retrograde amnesia occurred in free recall, but not in primed word-stem completion.     

Intrusive re-experiencing in post-traumatic stress disorder: phenomenology, theory, and therapy

The article describes features of trauma memories in post-traumatic stress disorder (PTSD), including characteristics of unintentional re-experiencing symptoms and intentional recall of trauma narratives. Reexperiencing symptoms are usually sensory impressions and emotional responses from the trauma that appear to lack a time perspective and a context. The vast majority of intrusive memories can be interpreted as re-experiencing of warning signals, i.e., stimuli that signalled the onset of the trauma or of moments when the meaning of the event changed for the worse. Triggers of re-experiencing symptoms include stimuli that have perceptual similarity to cues accompanying the traumatic event. Intentional recall of the trauma in PTSD may be characterised by confusion about temporal order, and difficulty in accessing important details, both of which contribute to problematic appraisals. Recall tends to be disjointed. When patients with PTSD deliberately recall the worst moments of the trauma, they often do not access other relevant (usually subsequent) information that would correct impressions/predictions made at the time. A theoretical analysis of re-experiencing symptoms and their triggers is offered, and implications for treatment are discussed. These include the need to actively incorporate updating information ("I know now ...") into the worst moments of the trauma memory, and to train patients to discriminate between the stimuli that were present during the trauma ("then") and the innocuous triggers of re-experiencing symptoms ("now").     

Overgeneral autobiographical memory recollection in Iranian combat veterans with posttraumatic stress disorder

This study examined the recollection of autobiographical material in memory among Iranian military veterans with and without posttraumatic stress disorder (PTSD), and healthy non-trauma-exposed control subjects. Participants completed the Autobiographical Memory Test, Autobiographical Memory Interview (counterbalanced), Impact of Event Scale-Revised, Beck Depression Inventory-II, Wechsler Memory Scale-III and Wechsler Adult Intelligence Scale-Revised. The PTSD group generated fewer specific episodic and semantic details of autobiographical memory compared to the non-PTSD and control groups. Working memory did not significantly moderate the relationship between PTSD diagnosis and reduced autobiographical memory specificity but did moderate the relationship between PTSD diagnosis and semantic recall; semantic memory recall was not significantly related to working memory ability for those with PTSD but was related to working memory ability for trauma survivors without PTSD. While the data provide some support for the expectation that higher working memory ability is associated with an increased ability to retrieve specific memories (i.e. semantic memory recall in those without PTSD), the findings are also consistent with the view that for those with PTSD the demands on working memory required for affect regulation cancel out this influence of working memory in augmenting access to specific memories.     

Traumatische Erfahrungen und Posttraumatische Belastungsstörung bei Journalisten

A questionnaire study on work-related trauma of journalists was conducted on the internet. 61 journalists (22 women) provided information about the type and frequency of highly stressful assignments and traumatic life events, symptoms of post-traumatic stress disorder (PCL-C), depression (CES-D) and coping style (emotional competence, FAPK, 3; sense of coherence, SOC). 46% of the participants lived in the USA, 41% in Europe; their mean age was 37 years and they had an average job experience of 13 years. They reported an average of 81 assignments in which they had been confronted with seriously injured, dying or dead persons or had worked at the risk of their own life. 13% had developed a full and 15% a partial post-traumatic stress disorder (PTSD). Compared to less disturbed individuals, the participants with (full or partial) PTSD reported significantly more often about violence in their original families, depressive symptoms and deficiencies in their emotional competence.     

Can implicit measures detect source information in crime-related amnesia?

Participants who are asked to simulate amnesia for a mock crime have a weaker memory for this event when they have to give up their role as a feigner, than those who are not asked to feign memory loss. According to the source monitoring framework (SMF), this memory-undermining effect of simulating amnesia for a crime would be due to misattribution of the right source of information. However, we know that the content of self-generated information (e.g., feigned version of the crime) might be preserved and recognised over time as a result of elaborative cognitive processing. In the present study, we aimed to contrast these two explanations. We showed participants a mock crime video and we instructed them to either feign amnesia (simulators) or confess the mock crime (confessors). Next, a free recall memory test was administered. After one week, participants were asked to perform a personalised source monitoring task using the autobiographical Implicit Association Test (aIAT). As predicted, we found that simulators were able to discriminate the content of their self-generated feigned story of the crime from the original version. Moreover, simulators were quicker than confessors at the aIAT task. Practical and theoretical implications of our results are discussed.     

Interidentity amnesia for neutral,episodic information in dissociative identity disorder

Interidentity amnesia is considered a hallmark of dissociative identity disorder (DID) in clinical practice. In this study, objective methods of testing episodic memory transfer between identities were used. Tests of both recall (interference paradigm) and recognition were used. A sample of 31 DID patients was included. Additionally, 50 control subjects participated, half functioning as normal controls and the other half simulating interidentity amnesia. Twenty-one patients subjectively reported complete one-way amnesia for the learning episode. However, objectively, neither recall nor recognition scores of patients were different from those of normal controls. It is suggested that clinical models of amnesia in DID may be specified to exclude episodic memory impairments for emotionally neutral material.     

Differential Predictors of Transient Stress Versus Posttraumatic Stress Disorder: Evaluating Risk Following Targeted Mass Violence

Schools have become a common incident site for targeted mass violence, including mass shootings. Although exposure to mass violence can result in significant distress, most individuals are able to fully recover over time, while a minority develop more pervasive pathology, such as PTSD. The present study investigated how several pre- and posttrauma factors predict posttraumatic stress symptoms (PTSS) in both the acute and distal aftermath of a campus mass shooting using a sample with known levels of pretrauma functioning (N = 573). Although the largest proportion of participants evidenced resilience following exposure to the event (46.1%), many reported high rates of PTSS shortly after the shooting (42.1%) and a smaller proportion (11.9%) met criteria for probable PTSD both in the acute and more distal aftermath of the event. While several preshooting factors predicted heightened PTSS after the shooting, prior trauma exposure was the only preshooting variable shown to significantly differentiate between those who experienced transient versus prolonged distress. Among postshooting predictors, individuals reporting greater emotion dysregulation and peritraumatic dissociative experiences were over four times more likely to have elevated PTSS 8 months postshooting compared with those reporting less dysregulation and dissociative experiences. Individuals with less exposure to the shooting, fewer prior traumatic experiences, and greater satisfaction with social support were more likely to recover from acute distress. Overall, results suggest that, while pretrauma factors may differentiate between those who are resilient in the aftermath of a mass shooting and those who experience heightened distress, several event-level and posttrauma coping factors help distinguish between those who eventually recover and those whose PTSD symptoms persist over time.     

Retrograde amnesia in patients with hippocampal, medial temporal, temporal lobe, or frontal pathology

There is considerable controversy concerning the theoretical basis of retrograde amnesia (R.A.). In the present paper, we compare medial temporal, medial plus lateral temporal, and frontal lesion patients on a new autobiographical memory task and measures of the more semantic aspects of memory (famous faces and news events). Only those patients with damage extending beyond the medial temporal cortex into the lateral temporal regions showed severe impairment on free recall remote memory tasks, and this held for both the autobiographical and the more semantic memory tests. However, on t-test analysis, the medial temporal group was impaired in retrieving recent autobiographical memories. Within the medial temporal group, those patients who had combined hippocampal and parahippocampal atrophy (H+) on quantified MRI performed somewhat worse on the semantic tasks than those with atrophy confined to the hippocampi (H-), but scores were very similar on autobiographical episodic recall. Correlational analyses with regional MRI volumes showed that lateral temporal volume was correlated significantly with performance on all three retrograde amnesia tests. The findings are discussed in terms of consolidation, reconsolidation, and multiple trace theory: We suggest that a widely distributed network of regions underlies the retrieval of past memories, and that the extent of lateral temporal damage appears to be critical to the emergence of a severe remote memory impairment.     

Children remember early childhood: long‐term recall across the offset of childhood amnesia

Young children's verbal recall for personally experienced events was examined over extended time periods across the traditional boundary of childhood amnesia. Forty children, aged 5½, discussed with an experimenter personal experiences that had taken place when they were as young as 1½. At 5½ children had not yet forgotten at least some events from before age 3½, the average offset of childhood amnesia. There was a qualitative shift in children's recall for events that occurred before age 2; for events that happened before age 2, only around half of children's recall was accurate. For events that occurred after this age, over 75% of children's recall was accurate. Complete forgetting of very early childhood has not yet occurred by age 5½. Copyright © 2007 John Wiley & Sons, Ltd.     

Treatment outcome for chronic PTSD among female assault victims with borderline personality characteristics: a preliminary examination

The present study examined the effect of the presence of borderline personality disorder characteristics (BPC) on patients' responses to cognitive behavioral treatment for chronic PTSD. Seventy-two female victims of sexual and non-sexual assault were randomly assigned to one of four treatment conditions: prolonged exposure (PE), stress inoculation training (SIT), combined treatment (PE/SIT), and wait list control (WL). Treatment consisted of nine bi-weekly individual sessions. Seventeen percent of the patients met full (10%) or partial criteria (7%) for borderline personality disorder. A greater number of patients with BPC reported sexual assault in childhood compared to those without the symptomatology. Patients with BPC also reported more pre-treatment anger. In general, those with BPC benefited significantly from treatment, although at post-treatment, they were less likely to achieve good end-state functioning than those without such symptomatology. The relationship between BPC and treatment response will be discussed.     

Does feigning amnesia impair subsequent recall?

Defendants who are accused of serious crimes sometimes feign amnesia to evade criminal responsibility. Previous research has suggested that feigning amnesia might impair subsequent recall. In two experiments, participants read and heard a story about a central character, described as “you,” who was responsible for the death of either a puppy (Experiment 1) or a friend (Experiment 2). On free and cued recall tests immediately after the story, participants who had feigned amnesia recalled less than did participants who had recalled accurately. One week later, when all participants recalled accurately, participants who had previously feigned amnesia still performed worse than did participants who had recalled accurately both times. However, the participants who had formerly feigned amnesia did not perform worse than did a control group who had received only the delayed recall tests. Our results suggest that a “feigned amnesia effect” may reflect nothing more than differential practice at recall. Feigning amnesia for a crime need not impair memory for that crime when a person later seeks to remember accurately.     

Mild Traumatic Brain Injury and Posttraumatic Stress Disorder in Returning Iraq and Afghanistan War Veterans: Implications for Assessment and Diagnosis

Mild traumatic brain injury (MTBI) and posttraumatic stress disorder (PTSD) are considered the “signature injuries” of combat soldiers returning from Iraq and Afghanistan. Both disorders can greatly affect the functioning of soldiers, yet the disorders often go undetected or are misdiagnosed by both military and civilian health care providers. This article provides information about MTBI and PTSD in returning combat soldiers along with implications for assessment and diagnosis.     

The relationship between induced emotional arousal and amnesia

An experiment was conducted to test a hypothesis emanating from a similarity in data pattern between studies on amnesia and studies on the effects of arousal on memory. The hypothesis was that arousal and amnesia might be related, or more precisely, that amnesia induced in the laboratory might be mediated by high levels of arousal. Subjects in this experiment were presented with a thematic, short story in pictorial form. One version of the story consisted of a traumatic, arousal-inducing event placed between neutral events. A second version of the story contained the same neutral events in the beginning and the end, but also a neutral event in the middle. Palmar skin conductance, heart rate, and subjective self-ratings were used to determine that the manipulation made had caused different degrees of emotional arousal for the two groups of subjects presented with the different versions of the story. The methods used to determine memory performance were recall and recognition. The data obtained indicate that amnesia induced in the laboratory is mediated by emotional arousal in terms of concepts of attention and reconstruction.     

Victimization and PTSD in a Faroese youth total-population sample

Petersen, T., Elklit, A. & Olesen, J. G. (2010). Victimization and PTSD in a Faroese youth total-population sample. Scandinavian Journal of Psychology, 51, 56–62.
The prevalence of twenty traumatic events and negative life events in relation to posttraumatic stress disorder (PTSD) was studied in a Faroese total-population sample of 687 eighth-grade students with a mean age of 14.2 years. Ninety-four percent of the females and 89% of the males were directly exposed to or had witnessed at least one traumatic event or a negative life event. The odds ratios for PTSD after direct and indirect exposure to specific events are described. The lifetime prevalence of PTSD was 20%, whereas another 14% reached a subclinical level of PTSD. After exposure, females had PTSD more than twice as often as males. Being exposed to multiple traumatic events, living with a single parent, and having experienced a traumatic event or a negative life event within the last year were all associated with PTSD and its subscales.